Many people told us that San Pedro would be expensive but we got a dinner with starter, main course, dessert and a Pisco Sour for 5500.- Chilean pesos (= CHF 11.-), so not too bad!
The busride from Salta to San Pedro de Atacama took about ten hours and went over the Jama Pass which is at 4800m asl. I defintely moved too quickly at the top as I noticed the altitude. You just have to take it slower as usual and another tip is to drink enough water if you don't want to get height sickness. The Argentinan border control is also on top whereas the Chilean one is directly in San Pedro de Atacama itself. As we weren't able to book beds online ahead we were quite grateful that two people were waiting in the town and were offering rooms.The lady from the second place offered to drive us to her place first and then to the other one. Hers was double the price and a bit away from the center so that we took the other one but of course gave her something for driving us. Especially as her car broke down after dropping us off at the hostal.